Sulfo group-containing azo compounds having a tetrazo component radical derived from an optionally substituted 3,8-diaminodibenzofuran

ABSTRACT

Dyes of the formula ##STR1## AND SUBSTITUTED DERIVATIVES THEREOF, WHEREIN R is a coupling component radical, 
     R 1  is a coupling component radical, with the proviso that R and R 1  are different, and 
     N is 1 to 8, 
     Are disclosed. They are useful for dyeing and printing natural and synthetic polyamides, cotton and other cellulosic fibers, polypropylene fibers modified by basic groups, synthetic polyamides and polyesters modified by acid groups, paper and leather. They exhibit good fastness to light, wet treatments and abrasion.

This application is a continuation in-part of our copending applicationSer. No. 376,512, filed July 5, 1973, and now abandoned.

This invention relates to new dibenzofuran derived azo dyestuffscontaining sulphonic acid groups.

The invention provides compounds of formula I, ##STR2## in which Rsignifies the radical of a coupling component, R₁ signifies the radicalof a coupling component differing from R, and

n signifies an integer from 1 to 8,

And the aromatic rings A and/or B may be unsubstituted or substituted bya substituent usual in azo chemistry, and the sulphonic acid group orgroups may be present on rings A or B or in radicals R and R₁. R, R₁ andrings A and B, independently may be substituted, for example, bymetallizable and/or fiber-reactive groups. The compounds may be inmetallized form.

The invention thus concerns asymmetric disazo and polyazo dyestuffshaving at least one sulphonic acid group, whereby the --SO₃ H groups mayoccur in the aromatic rings A and/or B and/or in the radicals R or R₁.The azo compounds of formula I preferably contain p-sulphonic acidgroups, p standing for 1, 2, 3 or 4, and the --SO₃ H group or groupsoccur mainly in the radicals R and/or R₁. Dyestuffs in which thearomatic rings A and B carry no further substituents are to beemphasized in particular. The invention embraces especially azocompounds of the formula: ##STR3## in which q signifies 1, 2 or 3, azocompounds of the formulae: ##STR4## in which r signifies 1 or 2 or:##STR5## R, R₁ and rings A and B being as defined above.

The invention also embraces azo compounds of the formulae: ##STR6## inwhich R₂ signifies an arylene radical which is unsubstituted orsubstituted, and

R₃ signifies a hydrocarbon radical or acyl radical which isunsubstituted or substituted,

R₁ and rings A and B being as defined above.

In the compounds of formulae VI and VII, p preferably signifies 1, 2, 3or 4.

Other preferred compounds are of the formula: ##STR7## in which tsignifies 0 or 1.

Similarly interesting azo compounds have the formula: ##STR8## in whichR_(2') denotes an optionally substituted arylene radical differing fromR₂, or azo compounds of the formula: ##STR9##

The aromatic rings R₂ and/or R_(2') may be substituted in the compoundsof formulae XII and XIII by carboxylic acid groups and/or sulphonamidegroups.

Similarly interesting azo compounds conform to the formula: ##STR10## inwhich X signifies a direct bond or bi- or tri- valent bridge member,

Y signifies a fibre-reactive radical, and v signifies 2, 3 or 4.

The compounds of formula XV contain preferably 3 or 4 sulphonic acidgroups, such groups preferably being on the R and R₁ groups.

Other compounds of formula I are those of the formulae: ##STR11## or inparticular of the formulae: ##STR12## in which w signifies 2 or 3.

As examples of fibre-reactive groups, e.g. for the radical Y, in thecompounds of the invention, there may be given the radical of di- ortrihalogen-1,3,5-triazines, or di-, tri- or tetra-halopyrimidines,alkylsulphonyl halogen pyrimidines, or else acyl radicals carrying asubstituent detachable as an anion and/or a --C--C-multiple bond capableof addition. Such compounds are described, for example, in the BritishPat. Nos. 1,144,477 and 1,145,385. Suitable reactive groups, forinstance, are chloroacetyl, beta-chloropropionyl, alpha-chloroacryloyl,2,3-dichloroquinoxdyl-6-carbonyl,beta-(4,5-dichloropyridazonyl-1)-propionyl,4,6-dichloro-1,3,5-triazinyl-2, 2,6-dichloropyrimidyl-4,2,5,6-trichloropyrimidyl-4, 4-chloro-6-amino-1,3,5-triazinyl-2,4-chloro-6-(4'-sulphophenylamino)-1,3,5-triazinyl-2,5-chloro-2,6-difluoropyrimidyl-4,β-sulfatoethylsulfonyl, or ##STR13##

Other compounds of formula I are of the formula: ##STR14## in which R₄signifies an alkyl radical of low molecular weight which isunsubstituted or substituted, in particular the methyl of ethyl radical,or a phenylsulfonyl radical of the formulae: ##STR15## and R' signifiesthe radical of a coupling component of the benzene, pyrazolone-5,aminopyrazole, naphthalene or heterocyclic series or the radical of anacetoacetylamino compound, and the aromatic rings Z₁ and/or Z₂ areunsubstituted or substituted. The acetoacetylamino compound may beunsubstituted or N-substituted.

More specifically, the foregoing groups include the compounds of theformulae: ##STR16## or in particular those of the formulae: ##STR17## inwhich R₅ is an alkyl or aryl radical substituted by q --SO₃ H groups,preferably by 1 or 2 sulphonic acid groups, and otherwise unsubstitutedor further substituted, such as a phenyl or naphthyl radical, or azocompounds of the formula: ##STR18## or azo compounds of the formula:##STR19## in which R₆ signifies --OH, --O--SO₂ --R₉ or a radical of theformula ##STR20## R₇ signifies hydrogen or an acyl or hydrocarbonradical which is unsubstituted or substituted, for example an optionallysubstituted alkyl, phenyl or naphthyl radical,

R₈ signifies an alkyl or alkoxy radical of low molecular weight which isunsubstituted or substituted, acetyl, carboxyl or carboxylic acid amideradical,

R₉ signifies a hydrocarbon radical which is unsubstituted orsubstituted,

R₁₀ signifies hydrogen or a hydrocarbon radical which is unsubstitutedor substituted,

as azo compounds of the formula: ##STR21##

There are likewise suitable azo compounds of the formula: ##STR22## inwhich the aromatic ring Z₃ is substituted by a substituent makingcoupling possible, for example a hydroxyl or amino group, e.g. aprimary, secondary or tertiary amino group, or azo compounds of theformula: ##STR23## or of the formula ##STR24## or of the formula##STR25## or of the formula ##STR26## or of the formula ##STR27## or ofthe formula ##STR28## in which the aromatic ring Z₄ is substituted by asubstituent making coupling possible, such as a hydroxyl or amino group,e.g. by a primary, secondary or tertiary amino group, or the formula:##STR29## in which the aromatic rings Z₅ and Z₆ are substituted by asubstituent making coupling possible, such as a hydroxyl or amino group,e.g. by a primary, secondary or tertiary amino group or of the formula:##STR30## or of the formula: ##STR31## or of the formula: ##STR32## orof the formula: ##STR33## or of the formula: ##STR34## or of theformula: ##STR35## or of the formula: ##STR36## or of the formula:##STR37## or of the formula: ##STR38## or of the formula: ##STR39## orof the formula: ##STR40## or of the formula: ##STR41## or of theformula: ##STR42## or of the formula: ##STR43## or of the formula:##STR44## or of the formula: ##STR45## or of the formula: ##STR46## orof the formula: ##STR47## or of the formula: ##STR48## or of theformula: ##STR49## Similarly suitable azo compounds conform to theformulae: ##STR50## in which R' signifies the radical of a couplingcomponent of the benzene, pyrazolone-5, aminopyrazole, naphthalene orhetero cyclic series or the radical of an acetoacetylamino compound,

X₁ signifies a bivalent bridge member, such as an alkylene or aryleneradical which is unsubstituted or substituted, ##STR51## Y is theradical of a fibre-reactive compound, and V signifies 2, 3 or 4

and the aromatic ring Z₇ is substituted by a substituent making couplingpossible and otherwise unsubstituted or substituted,

or of the formula: ##STR52##

Suitable reactive groups are for instance the radicals alreadymentioned, or in particular4,6-di-chloro-1,3,5-triazinyl-2,2,6-dichloro-or 2,6-difluoropyrimidyl-4.

Suitable compounds of this type are of the formula: ##STR53## in whichone or two X₂ signifies hydrogen and the others signify chlorine,bromine or fluorine,

or compounds of the formula: ##STR54## in which X₃ signifies hydrogen,chlorine bromine

or fluorine, and

X₄ signifies chlorine, bromine or fluorine,

or in particular of the formula: ##STR55##

By analogy all the compounds of the formulae LXX to LXXIII may be ofsimilar structure to those of formulae II to VII or XVI to XXI withregard to their asymmetric structure and the position of the --SO₃ Hgroups in the molecule.

The invention also includes those azo compounds of formula I in which Rand/or R₁ denote radicals of compounds containing metals; the new azocompounds of formula I may be used also to produce metalliferouscompounds of formula I, if compounds of formula I in which the aromaticrings A and/or B and/or the radicals R and/or R₁ contain groups capableof forming metallic complexes and occupying an advantageous orthoposition to the azo groups are treated in the substance or on the fibrewith metal-releasing compounds. Thus they may be, for example, 1:1and/or 1:2 metal complex dyestuffs. Accordingly, they may contain ametal atom such as iron, cobalt, copper, nickel, manganese, aluminumchromium or zinc in a complex bond.

The dyestuffs indicated below may be obtained as metal complex dyestuffsby metallizing the corresponding non-metalliferous dyestuffs, which canbe done during manufacture or on the fibre, using known methods. Theycorrespond to the formula: ##STR56## or of the formula: ##STR57## inwhich R'₁₀ and R'₁₁ signify the radical of a coupling component of thebenzene, pyrazolone-5, aminopyrazole, naphthalene or acetoacetylaminoseries,

X₅ and X₆ signify --NH--R₁₀, --O-- or --COO--, and are preferably inortho positions to the azo group,

and Me is a metal atom such as copper, nickel, iron, cobalt, manganeseor chromium,

or of the formula ##STR58## or of the formula ##STR59## or of theformula: ##STR60## or in particular of the formula: ##STR61## in whichthe aromatic rings Z₈ and/or Z₉ and/or Z₁₀ may be further substituted.Me preferably signifies Cu.

By analogy all the compounds of the formulae LXXIV to LXXIX may be ofsimilar structure to those of the formulae II or VII or XVI to XXI inrespect of their asymmetric structure and the position of the --SO₃ Hgroups in the molecule.

Preferred polyazo compounds correspond mainly to the formula: ##STR62##in which R₁₂ signifies the radical of a coupling

component of the benzene, pyrazolone-5, aminopyrazole or naphthaleneseries,

R₁₃ signifies the radical of a diazo or coupling component of thebenzene or naphthalene series, and

t signifies 0 or 1.

Examples of R₁₂ are hydroxy- and dihydroxybenzene and amino- anddiamine-benzene.

Examples of R₁₃ are aminobenzenesulphonic acid,aminonaphthalenesulphonic acid, etc.

Suitable coupling components, such aS R, R₁, R₂, R'₂, R', R'₁₀, R'₁₁,R₁₂ and R₁₃, are those of the aromatic series, e.g. those of the benzeneor naphthalene series carrying a substituent which makes the couplingpossible. They belong for instance to the aminobenzene, hydroxybenzene,aminonaphthalene or hydroxynaphthalene series. Coupling components ofthe heterocyclic series may be employed too, such as those of thepyrazole (e.g. the pyrazolone-5 or aminopyrazole series), quinoline,hydroxyquinoline, barbituric acid, indole or carbazole series. Equallysuited are coupling components with a methylene group capable of furthercoupling; and for example acylacetylamino compounds likeacylacetylaminoalkyl or aryl compounds.

Examples of suitable coupling components are:

alkylphenols,

1,3-dihydroxybenzene,

2-hydroxynaphthalene,

1-hydroxy-4-alkoxynaphthalenes,

2-hydroxy-8-acetylamino-6-methylsulphonylaminonaphthalene,

1-hydroxy-6- and 7-aminonaphthalene,

1-hydroxy-6- and 7-methylaminonaphthalene,

1-hydroxg-6- and 7-phenylaminonaphthalene,

1-hydroxy-(4'-methoxyphenylamino)-naphthalene,

1-hydroxy-(2',4 ',6'-trimethylphenylamino)naphthalene, etc.

Aromatic coupling components with a primary or secondary amino group,such as aminobenzene and its derivatives, e.g.,

1,3-diaminobenzene,

1-aminonaphthalene,

2-aminonaphthalene,

2-phenylaminonaphthalene,

2-methylamino-5-hydroxynaphthalene,

2-hydroxynaphthalenesulfonic sulphonic acids such as

2-hydroxynaphthalene-4-, 5-, 6-, 7- or 8-. sulphonic acid;2-hydroxynaphthalenesulfonic acids disulphonic acid such as2-hydroxynaphthalene-4,6-, 4,7-, 4,8-, 5,8-, and 6,8- disulphonic acids,2-amino-8-hydroxynaphthalene-6-sulphonic acid,1-aminonaphthalene-4-sulphonic acid, 1-hydroxynapthalene-3,6-disulphonic acid; 1-hydroxynapthalene trisulphonic acids such as1-hydroxynaphthalene-3,6,8-trisulphonic acid.

Heterocyclic components are for instance 1-phenyl-3-methylpyrazolone-5,

1-(sulphophenyl)-3-methylpyrazolone

1-chlorophenyl)-3-methylpyrazolone-5,

1-(cyanophenyl)-3-methylpyrazolone-5,

1-(3'-halophenyl)-3-methylpyrazo lone-5,

1-(3'-cyanophenyl)-3-methylpyrazolone-5,

1-(alkylphenyl)-3-methylpyrazolone-5, and

1-(di- or trialkylphenyl)-3-methylpyrazolone 5

Aliphatic coupling components with an active methylene group are forexample:

1-acetoacetylarylamides like

1-acetoacetylaminobenzene etc.,

1-acetoacetylamino-2-ethylhexane, 1-acetoacetylaminobutane etc.

The coupling components and all radicals of aromatic character may besubstituted by substituents usual in dyestuffs chemistry, e.g. byhalogen atoms, nitro and amino such as primary, secondary or tertiaryamino, cyano, thiocyano, hydroxyl, alkyl, alkoxy, trifluoroalkyl,trichloroalkyl, mercapto, alkyl- or phenylmercapto, phenyl, cycloalkyl,phenoxy, alkylamino, dialkylamino, phenylamino, acyl, acyloxy, --COOH,--SO₃ H; acylamino and sulphonarylamide groups like acetylamino,benzoylamino, alkylsulphonyl, arylsulphonyl, sulphonamide,sulphonalkylamide, sulphondialkylamide; arylazo such as phenylazo,diphenylazo etc,. Preferred acyl groups correspond to the formula R₁₄--Y₁ or R₁₄ '--Z--, in which R₁₄ is a hydrocarbon radical substituted asrequired, carrying the substituents listed above and/or containinghereto atoms, preferably an alkyl or phenyl radical substituted asrequired, most preferably unsubstituted C₁₋₄ alkyl or phenyl.

Y₁ is a radical of the formula --O--CO--, --SO₂ -- or --O --SO₂₋₋, R₁₄'is a hydrogen atom or has one of the significances of R₁₄.

Z is a radical of the formula --CO--, --NR₁₄ "--CO-or --NR₁₄ "--SO₂ --and R₁₄ " denotes a hydrogen atom or one of the significances of R₁₄.

Halogen stands for bromine, fluorine or iodine, though in particular forchlorine.

Preferred salt forms of the compounds of formula I are the alkali metal,e.g. sodium potassium and lithium salt forms, the ammonium salt formsand the mono-, di- and tri-C₁₋₄ -alkyl- and C₁₋₄ hydroxyalkylammoniumsalt forms. The most preferred such forms being the alkali metal andammonium salt forms, particularly the sodium salt forms.

Hydrocarbon radicals denote alkyl, aryl or cycloalkyl radicals mainly.Alkyl radicals may have 1 to 18, 1 to 12, though preferably 1 to 6,carbon atoms; preferably also they denote alkyl radicals of lowmolecular weight with 1, 2, 3 or 4 carbon atoms. Aryl or aryleneradicals stand chiefly for phenyl or naphthyl radicals, or elsephenylene or naphthylene radicals capable of carrying the above-namedsubstituents. Cycloalkyl radicals are preferably 5- or 6-link ringsystems though more preferably cyclohexyl radicals which may besubstituted by alkyl, alkoxy or halogen as necessary.

Alkoxy radicals contain preferably 1, 2, 3 or 4 carbon atoms in thealkyl radical. As examples of bivalent links, e.g. X and X₁, may begiven unsubstituted or substituted C₁₋₁₂ alkylene or arylene radicals,which former radicals may be preceded, interrupted or followed by ahetero atom or group containing hetero atoms, e.g. by ##STR63## --O--,--S--, or --N (R₁₀)-- where R₁₀ is as defined above preferably hydrogenor C₁₋₄ alkyl.

Preferred substituents in the aromatic rings Z₁ to Z₁₀ are for examplehalogen, alkyl or alkoxy.

These rings Z₁ to Z₁₀ may also have a --CH═CH--CH═--CH═CH--CH═CH--groups condensed thereon.

the compounds provided by the present invention which are of particularinterest may be represented by formula IA, ##STR64## in which Ra andR_(1a) are different and each signifies a coupling component of thebenzene, naphthalene, pyrazolone-5 or aminopyrazole series or anacetoacetylamino radical,

X signifies hydrogen or --SO₃ H, and

pa signifies 1, 2, 3 or 4,

the compounds optionally bearing metallised or fibre reactive groups andbeing in free acid or salt form.

As a first class compounds falling within the general formula IA, may begiven the compounds of formula IAa, ##STR65## in which X is as definedabove, and R_(2a) and R_(3a), which are different, either each signifiesa radical selected from those of formulae (a), (b), (c) and (d),##STR66## in which R_(4a) signifies hydrogen, hydroxy, --SO₃ H or agroup of the formula ##STR67## and R_(5a) signifies hydroxy, amino,carboxyl, N,N-di(C₁₋₄)alkylamino,N-(C₁₋₄)-alkyl-N-(C₁₋₄)alkylphenylamino,N-(C₁₋₄)alkyl-N-(C₁₋₄)alkylphenylaminosulphonyl, N-phenylamino,N-(C₁₋₄)alkylamino or N-(C₁₋₄)alkyl-N-benzylamino, ##STR68## in whichR_(6a) signifies --NH₂ or --OH,

R_(7a) and R_(8a), independently, signify hydrogen, C₁₋₄ alkyl, halogenor --SO₃ H, and

R_(9a) signifies hydrogen, C₁₋₄ alkyl, halogen or cyano, ##STR69## inwhich R_(10a) signifies --OH, --NH₂ or acetylamino,

R_(11a) signifies hydrogen, carboxyl or --OH,

R_(12a) signifies hydrogen, --SO₃ H,C₁₋₄ alkyl, C₁₋₄ alkylsulphonyl,C₁₋₄ alkoxy, C₁₋₄ -alkylamino, phenylamino, C₁₋₄ -alkoxyphenylamino ortrimethylphenylamino, and

R_(13a) and R_(14a), independently, signify hydrogen or --SO₃ H,##STR70## in which R_(15a) signifies 2-ethylhexyl, butyl,

C₁₋₄ -(alkyl)phenyl, C₁₋₄ -alkoxyphenyl, di-(C₁₋₄)alkoxyphenyl, phenylor disulfonaphthyl

or one of R_(2a) and R_(3a) signifies a radical selected from thefollowing formulae (e), (f), (g), (h) and (i), the other signifying aradical of the above formulae (a), (b), (c) and (d), ##STR71## in whichR_(16a) signifies C₁₋₄ -alkyl or ##STR72## in which R_(17a) signifieshydrogen or C₁₋₄ alkyl,

and

R_(18a) signifies hydrogen or C₁₋₄ alkyl, ##STR73## in which R_(16a) isas defined above, ##STR74## in which R_(19a) signifies hydrogen or C₁₋₄-alkyl

R_(20a) signifies hydrogen, halogen, C₁₋₄ alkyl or C₁₋₄ alkoxy, and

R_(22a) signifies a 4,6-dichloro-1,3,5-triazinyl-2;2,6-dichloropyrimidyl-4; 2,5,6-trichloropyrimidyl-4;4-chloro-6-(4'-sulphophenylamino)-1,3,5-triazinyl-2;4-chloro-6-(phenylamino)1,3,5-triazinyl-2 or5-chloro-2,6-difluoropyrimidyl-4radical, ##STR75## in which R_(22a) isas defined above, and

R_(21a) signifies hydrogen or --SO₃ H, ##STR76## in which R_(22a) is asdefined above, or R_(2a) signifies a radical of formula (a), above, andR_(3a) signifies a radical of formula (j), ##STR77## the compounds offormula IAa containing 2, 3, or 4 sulphonic acid groups and being infree acid or salt form.

As will be appreciated, the radicals of formula (a) and (c) shouldcontain groups enabling coupling to take place.

In the compounds of formula IAa, the preferred radicals of formula (a)are of formulae (a¹) and (a²), ##STR78## in which R_(30a) signifiescarboxyl, hydroxyl,

N-(c₁₋₄)alkyl-N-(C₁₋₄)alkylphenylaminosulphonyl, N,N-di(C₁₋₄)alkylamino,N-mono-(C₁₋₄)-alkylamino, N-phenylamino,

N-(c₁₋₄)alkyl-N-benzylamino or ##STR79## and R_(31a) signfifies hydrogenor hydroxyl,

with the proviso that where R_(30a) signifies2-hydroxy-5-sulphophenylazo, R_(31a) signifies hydroxyl, ##STR80## thepreferred radicials of formula (b) being of formula (b¹) ##STR81## inwhich R_(33a) and R_(35a), independently, signify hydrogen or chlorine,and

R_(34a) signifies hydrogen, --SO₃ H or chlorine,

the preferred radicals of formula (c) being of formula (c¹) ##STR82## inwhich R_(36a) signifies +OH, --NH₂ or acetylamino,

R_(37a) signifies hydrogen, hydroxyl, carboxy or --SO₃ H, and

R_(38a), R_(39a) and R_(40a), independently, signify hydrogen or --SO₃H,

the radical of formula (c¹) containing from 1 to 3 --SO₃ H groups, thepreferred radicals of formula (d) being of formula (d¹), ##STR83## inwhich R_(41a) signifies phenyl, dimethoxyphenyl, methyl- ormethoxyphenyl, 2-ethylhexyl or disulfonaphthyl,

the preferred radicals of formula (e) being of formula (e¹) ##STR84## inwhich R_(42a) signifies methyl, ethyl, phenylsulphonyl orp-methylphenylsulphonyl, and

R_(43a) signifies hydrogen or methyl, the preferred radicals of formula(f) being of formula (f¹) ##STR85## in which R_(42a) is as definedabove, the preferred radicals of formula (g) being of formula (g¹),##STR86## in which R_(22a) is as defined above,

R_(44a) signifies hydrogen, methyl, chlorine or methoxy, and

R_(45a) signifies hydrogen or methyl, the preferred radicals of formula(h) being of formula (h¹) ##STR87## in which R_(22a) is as definedabove, and

R_(46a) signifies hydrogen or --SO₃ H, and the preferred radicals offormula (i) being of formula (i¹), ##STR88## in which R_(22a) is asdefined above.

As will be appreciated, the radicals of formula (a') and (c') shouldcontain groups enabling coupling to take place.

In the compounds of formula IAa, X preferably signifies hydrogen.

One group of interesting compounds of Formula IAa are those wherein oneof R_(2a) and R_(3a) is a group of formula (g), (h) or (i) and the otheris a group of formula (a), (b), (c) or (d). The preferred compounds ofthis group are those wherein any group of formula (g) is a group offormula (g¹), any group of formula (h) is a group of formula (h¹) andany group of formula (i) is a group of formula (l¹).

The most preferred compounds of formula IAa are those wherein Xsignifies hydrogen, R_(2a) signifies a radical of formula (e¹), (f¹),(g¹), (h¹) or (i¹) and R_(3a) signifies (a¹), (a²), (b¹), (c¹) or (d¹)or R_(2a) signifies a radical of formula (a¹), (a²), (b¹), (c¹) or (d¹)and R_(3a) signifies a radical of formula (e¹), (f¹), (g¹), (h¹) or (i¹)or R_(2a) signifies a radical of formula (a¹) and R_(3a) signifies aradical of formula (j).

As a second class of compounds falling within the general formula IA,may be given the compounds of formula IAb, ##STR89## in which Xsignifies hydrogen or -SO₃ H,

R_(2b) signifies a radical of formula (e) or (f) above, preferably offormula (e¹) or (f¹), above, and

R_(3b) signifies a radical of formula (k), (l) or (m), ##STR90## inwhich R_(23b), R_(24b) and R_(24b) 1, independently, signify hydrogen or-SO₃ H, and in which, of the two free bonds, one is in α-position, andthe other in adjacent β-position thereto, ##STR91## in which R_(25b)signifies hydrogen or --SO₃ H, ##STR92## in which R_(27b) signifieshydrogen or C₁₋₄ alkyl, the compounds of formula IAb containing 2, 3 or4 sulphonic acid groups and being in free acid or salt form.

The preferred compounds of formula IAb are those in which R_(2b)signifies a radical of formula (e¹) or (f¹) and R_(3b) signifies aradical of formula (k¹) or (l¹), ##STR93##

As a third class of compounds falling within the general formula IA, maybe given the compounds of formula IAc, ##STR94## ps in which R_(2c)signifies a radical of formula (e) or (f), above, preferably of formula(e¹) or (f¹), above, and

R_(3c) signifies a radical of formula (k), (l) or (m), above, preferablyof formula (k¹) or (l¹), above, the compounds of formula IAc containing2, 3 or 4 sulphonic acid groups and being in free acid or salt form.

As a fourth class of compounds falling within the general formula IA,may be given the compounds of formula IAd, ##STR95## in which the R_(3d)'s, which are different, each signifies a radical of formula (k), (l) or(m), above, the compounds of formula IAd containing 2, 3 or 4 sulphonicacid groups and being in free acid or salt form.

The invention also provides a process for the production of compounds offormula I, which comprises coupling a tetrazo compound from a diamine offormula Ia ##STR96## in which rings A and B are as defined above, with acoupling component of formula Ib,

    R--H                                                       Ib

in which R is as defined above, and with a coupling component of formulaIc,

    R.sub.1 --H                                                Ic

in which R₁ is as defined above.

It will be clear that the various preferred azo compounds describedhereinbefore may be prepared by coupling the appropriate startingmaterials. It will also be clear that once the basic dye structure isformed according to the invention, it may be modified in conventionalmanner.

Thus, for example, the azo compounds of formula VI or VII may beobtained by etherifying or acylating, e.g. tosylating, a compound of theformula: ##STR97## or a compound of the formula: ##STR98##

The azo compounds of formula XII may be obtained by etherifying oracylating, e.g. tosylating, a compound of the formula: ##STR99##

The azo compounds of formula XV can be obtained by coupling the diazocompound from an amino compound of the formula: ##STR100## in which y'may signify t, v or w, with a coupling component of the formula:

    (HO.sub.3 S).sub.y" --R.sub.1 --H

in which y' and y" total 2 to 4.

The azo compounds of formula XV can also be obtained by reacting acompound of the formula: ##STR101## with a compound which will provide afibre-reactive radical.

It is also clearly possible to employ compounds of formula Ia which aresubstituted by the SO₃ H group, such as the diamine of the formula:##STR102##

Such intermediates are known or may be prepared in conventional mannerfrom known starting materials.

The coupling reaction may be effected in conventional manner. It ispreferred to effect a first coupling in water at a pH of 6 to 8 andtemperatures from -10° to +20° C, more preferably at 5° to 10° andsuitably in the presence of a coupling accelerator like pyridine, urea,etc. The coupling of the resulting compound with the second couplingcomponent is also effected in water usually, at at a pH from 9 to 12,preferably between 10 and 11, at temperatures from -10° to +20° C,preferably from 10° to 20°. The usual coupling accelerators may be usedfor this coupling reaction too.

Acylation or tosylating is also effected in conventional manner and maybe effected in water at at a pH of 8 - 10, preferably around 9, and attemperatures from 30° to 80° C, e.g. around 50° C, working preferably inthe presence of sodium carbonate or disodium phosphate. A neutralsolvent may be added too, such as dichlorobenzene.

Etherification, e.g. with dimethyl or diethyl sulphate, is effectedmainly in water with a pH- of 8 to 10 and temperatures of 30° to 80° C,preferably 40° - 60° C and in the presence of, for instance, sodium orpotassium carbonate or bicarbonate.

The introduction of a reactive component, i.e. transposition of thehydrogen atom of a free --OH or free amino group with the halogen atomor a sulphate group of a reactive component, can likewise be effected inwater with a pH- of 5 to 7 and at temperatures from 20° to 40° C,chiefly in the presence of sodium acetate or sodium bicarbonate.

Metallization is generally performed in water at a pH- of 9 to 12 and attemperatures from 40° C to boiling point, preferably at 50° - 80° C andin the presence of sodium hydroxide. Metallization is preferablyeffected with metal-donating agents, such as those donating chromium,iron, cobalt, copper, manganese or nickel. Copper-donating compoundsinclude, for example, copper acetate, chloride and formate;nickel-donating compounds include nickel formate, acetate and sulphate;chromium-donating compounds are chromium trioxide, fluoride, sulphate,formate, and acetate and, chromium ammonium sulphate; sodium chromate orbichromate may be employed as well. Typical manganese-, cobalt- oriron-donating compounds are manganese, cobalt or iron formate, acetateor sulphate.

The compounds are highly coloured and are indicated for dyeing orprinting natural or synthetic polyamides, like wool, silk and nylon,cotton, mordanted cotton, cellulosic fibres or regenerated cellulosefibres, basically modified polypropylene fibres, synthetic polyamides orpolyesters modified by acid groups, as well as paper and leather. Thepolyazo compounds are particularly indicated for dyeing or printingleather.

The anionic compounds of formula I and their metal complexes havegenerally good light- and wet-fastness on the substrates named above,also good fastness to washing, milling and potting, water, perspiration,abrasion and sea water. The substrates are dyed in brilliant, leveltones with good migration. They have a good neutral affinity andbuild-up capability, and cover stripily dyeing nylon fabric. They havegood substantivity on cotton and paper. In addition they have goodfastness to solvents, acids and alkalis.

Natural and synthetic polyamides and cellulose fibres dyed with thecompounds of formula I which are reactive dyestuffs, possess goodlight-fastness and good resistance to water, sea water, milling andperspiration. Their fixation capacity is also very good.

The compounds may be used for dyeing or printing using methodsconventional for the broad class of dyestuff and appropriate for theparticular substrate.

An important group of dyestuffs - the so-called benzidine dyestuffs,i.e. those derived from benzidine - has been withdrawn from the marketbecause of the danger to health, or the cessation of the production ofthese dyestuffs is being considered. Consequently, there is a real needto replace this valuable group of dyestuffs by others of similar typeand shading. The compounds of the present invention are not derived frombenzidine, and it is thought that their production will be lessdangerous.

In the examples that follow, the parts are parts by weight, thepercentages are percentages by weight, and the temperatures are given indegrees Centigrade.

EXAMPLE 1

19.8 parts of 3,8-diaminodibenzofuran are suspended in 150 parts waterand 25 parts hydrochloric acid at 0° - 2°. Then a solution consisting of14 parts sodium nitrate in 60 parts water is dropped into thesuspension, keeping the temperature between 0° and 5°.

After 30 minutes a solution consisting of 22.4 parts2-hydroxynaphthalene-8-sulphonic acid, 8 parts sodium carbonate and 200parts water is dropped into the tetrazo solution. The coupling mass isstirred for 2 hours at 0° - 5°. After this a solution consisting of 25.4parts 1-(4'-sulfophenyl)-3-methyl-5-pyrazolone, 30 parts of a 30%aqueous sodium hydroxide solution and 100 parts water is added to thecoupling mass. The coupling mixture is stirred for 4 hours, during whichthe temperature may be allowed to rise to room temperature. The pH ofthe suspension is adjusted to 7, after which the dyestuff precipitatedis removed by suction, washed with an aqueous sodium chloride solutionand dried at 100°. The dyestuff will dye natural and syntheticpolyamides from neutral to weakly acid bath to a pure orange shade withgood wet- and light-fastness. The dyestuff of the formula: ##STR103##will also dye cotton, paper and leather with good fastnesses.

EXAMPLE 2

If the tetrazotized 3,8-diaminodibenzofuran is coupled first onto1-(4'-sulfophenyl)-3-methyl-5-pyrazolone and then onto2-hydroxynaphthalene-8-sulphonic acid under the reaction conditionsdescribed in Example 1, an isomer dyestuff is obtained with the formula:##STR104##

The dyestuff will dye natural and synthetic polyamide from neutral toweakly acid bath to a pure scarlet tone with the same good wet- andlight-fastness as the dyestuff described in Example 1.

In Table I that follows, the structure of further dyestuffs is given.These can be produced by the method indicated in Example 1, andcorrespond to the formula: ##STR105##

In the columns for R, R₁ and X' the initial compound and radicals forproducing the dyestuff (a) are given. A further column I gives thedyeing shade on synthetic polyamide (nylon), cellulose and leather.

                                      Table I                                     __________________________________________________________________________       Coupling component                                                                              Coupling component                                       No.                                                                              R             X'  R.sub.1         I                                        __________________________________________________________________________     3 2-hydroxynaphtha-                                                                           H   1-phenyl-3-methyl-                                                                            orange                                      lene-8-sulphonic  5-pyrazolone (4)                                            acid (4)                                                                    4 "             "   1-(4'-chloro)-phenyl-                                                                         orange                                                        3-methyl-5-pyrazolone                                                         (4)                                                       5 1-(2',5'-dichloro-                                                                          "   2-hydroxynaphthalene-                                                                         orange                                      4'-sulpho)-phenyl-                                                                              8-sulphonic acid (1)                                        3-methyl-5-pyrazolone                                                         (4)                                                                         6 2-hydroxynaphthalene                                                                        "   2-hydroxynaphthalene                                                                          scarlet                                  6,8-disulphonic  (1)                                                             acid (1)                                                                    7 "             "   1-hydroxynaphthalene                                                                          scarlet                                                       (2)                                                       8 1-hydroxynaphthalene-                                                                       "   "               red                                         3,6-disulphonic                                                               acid (2)                                                                    9 1-hydroxynaphthalene                                                                        H   1-phenyl-3-methyl-                                                                            orange                                   3,6-disulphonic  5-pyrazolone (4)                                                acid (2)                                                                   10 2-amino-8-    "   1-hydroxynaphthalene                                                                          red                                         hydroxynaphthalene                                                         4-sulphonic acid (2)                                                          6-sulphonic acid                                                                 (acid-coupled) (1)                                                         11 1-aminonaphthalene-                                                                         "   "               orange                                      4-sulphonic acid (2)                                                       12 1-phenyl-3-methyl-                                                                          "   1-amino-8-hydroxynaphthalene                                5-aminopyrazole (4)                                                        3,6-disulphonic acid                                                             red                                                                                             (alkaline-coupled) (7)                                   13 "             "   1-amino-8-hydroxynaphthalene                             4,6-disulphonic acid                                                             red                                                                                             (alkaline-coupled) (7)                                   14 N-ethyl-N-    H   2-hydroxynaphthalene-                                                                         red                                         benzylaniline-3'- 6-sulphonic acid (1)                                        sulphonic acid (4)                                                         15 n,n-diethylaniline (4)                                                                      H   "               red                                      16 N-methylaniline (4)                                                                         H   1-hydroxynaphthalene-                                                                         red                                                           3-sulphonic acid (2)                                     17 N-phenylaniline                                                                             H   "               red                                      18 N-ethyl-N-    H   2-hydroxybenzoic                                                                              red                                         benzylaniline-3'- acid (5)                                                    sulphonic acid (4)                                                         19 "             SO.sub.3 H                                                                        "               red                                      20 1-hydroxynaphthalene-                                                                       "   1-phenyl-3-methyl-5-                                                                          red                                         3,6-disulphonic   pyrazolone (4)                                              acid (2)                                                                   21 2-hydroxynaphthalene-                                                                       "   "               red                                         6-sulphonic acid (1)                                                       22 2-hydroxynaphthalene-                                                                       H   1-(4'-sulpho)-phenyl-3-                                                                       red                                         8-sulphonic acid (1)                                                                            methyl-5-pyrazolone                                                           (4)                                                      23 2-hydroxynaphthalene-                                                                       SO.sub.3 H                                                                        2-hydroxynaphthalene (1)                                                                      red                                         8-sulphonic acid (1)                                                       24 1-(4'-sulfophenyl-3-                                                                        "   2-hydroxynaphthalene-                                                                         red                                         methyl-5-pyrazolone (4)                                                                         8-sulphonic acid (1)                                     25 N-ethyl-N-benzylaniline                                                                     "   2-hydroxynaphthalene                                                                          red                                         (4)               (1)                                                      26 "             "   1-hydroxynaphthalene                                                                          red                                                           (2)                                                      27 "             "   2-hydroxynaphthalene-8-                                                                       red                                                           sulphonic acid (1)                                       28 N-ethyl-N-benzylaniline                                                                     "   1-hydroxynaphthalene                                                                          red                                      3'-sulphonic acid (4)                                                                          (2)                                                          29 1-acetoacetylamino-2,5-                                                                     "   2-hydroxynaphthalene-8-                                                                       orange                                      dimethoxybenzene (CH.sub.2)                                                                     sulphonic acid (1)                                       30 Acetoacetylaminobenzene                                                                     "   "               orange                                      (CH.sub.2)                                                                 31 Acetoacetic acid-                                                                           SO.sub.3 H                                                                        2-hydroxynaphthalene-                                                                         orange                                      o-anisidide (CH.sub.2)                                                                          8-sulphonic acid (1)                                     32 1-acetoacetylamino-                                                                         "   "               orange                                      2-ethylhexane (CH.sub.2)                                                   33 1-(4'-sulfophenyl-                                                                          "   Acetoacetylaminobenzene                                                                       yellow                                      3-methyl-5-pyrazolone                                                                           (CH.sub.2)                                                  (4)                                                                        34 N-ethyl-N-benzylaniline                                                                     "   1-hydroxynaphthalene-                                                                         red with                                    (4)               3-sulphonic acid (2)                                                                          bluish                                                                        tinge                                    35 1-hydroxynaphthalene-                                                                       H   1-phenyl-3-methyl-5-                                                                          orange                                      3,6,8-trisulphonic                                                                              pyrazolone (4)                                              acid (2)                                                                   36 2-hydroxynaphthalene-                                                                       H   "               orange                                      3,6,8-trisulphonic                                                            acid (1)                                                                   37 2-amino-8-        2-hydroxybenzoic                                                                              red                                         hydroxynaphthalene                                                                              acid (5)                                                 6-sulphonic acid                                                                 H                                                                             (acid coupling) (1)                                                        38 1-phenyl-3-methyl-                                                                          H   2-hydroxybenzene-1-                                                                           orange                                      5-pyrazolone-4'   carboxylic acid (5)                                         sulphonic acid (4)                                                         39 2,4,2'-trihydroxyazoben-                                                                        "               brown                                       zene-5'-sulphonic acid                                                                      H                                                               (3)                                                                        40 1-amino-8-    H   2-amino-8-      blue-                                       hydroxynaphthalene                                                                              hydroxynaphthalene-6-                                                                         black                                       3,6-disulphonic acid (7)                                                                        sulphonic acid (7)                                       41 1-phenyl-3-methyl-5-                                                                        H   1-hydroxynaphthalene-                                                                         orange                                      pyrazolone (4)    3,6,8-trisulphonic acid                                                       (2)                                                      42 "             H   2-hydroxynaphthalene-                                                                         orange                                                        3,6,8-trisulphonic acid                                  43 1-(4'-sulfophenyl)-                                                                         H   1-(4'-sulfophenyl)-3-                                                                         yellow                                      3-methyl-5-aminopyrazole                                                                        methyl-5-pyrazolone                                         (4)               (4)                                                      44 N-ethyl-benzylaniline                                                                       H   1-(4'-sulfophenyl)                                                                            yellow                                   3'-sulphonic acid (4)                                                                          3-methyl-5-pyrazolone (4)                                    45 2-hydroxynaphthalene                                                                        H   1-(2',5'-dichloro-4'-sulfo)                                                                   orange                                   8-sulphonic acid (1)                                                                           phenyl-3-methyl-5-                                                                pyrazolone (4)                                           46 2-hydroxynaphthalene                                                                        H   "               orange                                      (1)                                                                        47 "             H   2-hydroxynaphthalene-                                                                         scarlet                                                       6,8-disulphonic acid (1)                                 48 1-phenyl-3-methyl-5-                                                                        H   "               yellow                                      pyrazolone (4)                                                             49 "             H   2-hydroxynaphthalene-8-                                                                       yellow                                                        sulphonic acid (1)                                       50 "             SO.sub.3 H                                                                        "               yellow                                   51 "             "   1-hydroxynaphthalene-3-                                                                       scarlet                                                       sulphonic acid (2)                                       52 1-phenyl-3-methyl                                                                           SO.sub.3 H                                                                        2-hydroxynaphthalene-                                                                         yellow                                   5-pyrazolone (4) 6-sulphonic acid (1)                                         53 "             H   1-amino-8-      red with                                                      hydroxynaphthalene-3,6-                                                                       bluish                                                        disulphonic acid                                                                              tinge                                                         (alkaline-coupled) (7)                                   54 "             H   1-acetylamino-8-                                                                              "                                                             hydroxynaphthalene-3,6-                                                       disulphonic acid                                                              (alkaline-coupled) (7)                                    54a                                                                             2-hydroxynaphthalene                                                                        H   N-ethyl-N-ethyl phenyl-                                                                       scarlet                                  8-sulphonic acid (1)                                                                           aniline-3'-sulphonic acid                                                         (4)                                                       54b                                                                             2-hydroxybenzene-1-                                                                         H   1-phenyl-3-methyl-                                                                            "                                           carboxylic acid (5)                                                                             pyrazolone-5-                                                                 (4'-sulphonic acid) (4)                                  __________________________________________________________________________

EXAMPLE 55

31 Parts of 2-hydroxynaphthalene-6,8-disulphonic acid are dissolved in500 parts water, adding 15 parts sodium carbonate. This solution isdropped into the tetrazo solution produced as in Example 1. Afterstirring for 5 hours at 0° - 5° a solution consisting of 9.5 partsphenol, 25 parts sodium carbonate and 200 parts water is added to thecoupling mass. The coupling mixture is stirred for 4 hours, during whichthe temperature may rise to room temperature. After an intermediateisolation the disazo compound is stirred into 800 parts of water adding30 parts sodium carbonate, heated to 50°, and portions ofbenzenesulphonyl chloride are stirred in at this temperature. When nomore of the original substance can be detected in the thin-layerchromatogram, the suspension is cooled to 20°, filtered, washed with a2% aqueous sodium chloride solution and dried at 100°. The product willdye natural and synthetic polyamides to a pure scarlet tone with goodwet-, alkali-, light- and milling fastness. The dyestuff of the formula##STR106## dyes cotton, paper and leather with good fastness.

EXAMPLE 56

The free hydroxy group of the disazo dyestuff in Example 55 can also betransposed under the same conditions with diethyl sulphate instead ofthe benzenesulphonyl chloride. The dyestuff of formula ##STR107## isobtained, which dyes natural and synthetic polyamides in to scarlettones with good fastnesses. Table II gives the structures of furtherdyestuffs which can be produced according to the directions underExample 55.

They correspond to the formula ##STR108## in which the initial compoundsand radicals for producing the dyestuff (b) are given in the columns forR₁ and X'. Set out in the other columns are the radicals R₂ and R₃, andin a further column I is the dyeing shade on nylon, cellulose andleather.

                                      Table II                                    __________________________________________________________________________       Coupling component  Radical                                                                              Radical                                         No.                                                                                R.sub.1       X'  R.sub.2                                                                              R.sub.3    I                                    __________________________________________________________________________    57 2-hydroxynaphthalene- 6,8-disulphonic acid (1)                                                H                                                                                  ##STR109##                                                                           ##STR110##                                                                              scarlet                              58   "             H   "      CH.sub.3   "                                    59   "             H                                                                                  ##STR111##                                                                          "          "                                    60   "             H   "      C.sub.2 H.sub.5                                                                          "                                    61   "             H   "                                                                                     ##STR112##                                                                              "                                    62 1-hydroxynaphthalene-                                                                         H   "      "          "                                       3,6-disulphonic acid                                                          (2)                                                                        63   "             H                                                                                  ##STR113##                                                                          "          "                                    64   "             H   "      C.sub.2 H.sub.5                                                                          "                                    65   "             H   "      CH.sub.3   "                                    66 1-hydroxynaphthalene- 3-sulphonic acid (2)                                                    H   "                                                                                     ##STR114##                                                                              "                                    67   "             SO.sub.3 H                                                                        "      "          "                                    68   "             "   "      C.sub.2 H.sub.5                                                                          "                                    69 2-hydroxynaphthalene- 8-sulphonic acid (1)                                                    SO.sub.3 H                                                                         ##STR115##                                                                           ##STR116##                                                                              "-70   " " " C.sub.2 H.sub.5 "       71   "             H   "                                                                                     ##STR117##                                                                              "                                    72 1-(4'-sulfophenyl-                                                                            H   "      "          yellow                                  3-methyl-5-pyrazolone                                                         (4)                                                                        73 1-(2',5'-disulpho)-                                                                           H   "      "          "                                       phenyl-3-methyl-5-                                                            pyrazolone (4)                                                             74   "             H   "      C.sub.2 H.sub.5                                                                          "                                    75   "             H   "      CH.sub.3   "                                    76    "            H                                                                                  ##STR118##                                                                           ##STR119##                                                                              orange                               77 1-phenyl-3-methyl-5- pyrazolone-3'- sulphonic acid (4)                                        SO.sub.3 H                                                                         ##STR120##                                                                          "          yellow                               78 1-phenyl-3-methyl-5-                                                                          "   "      "          "                                       aminopyrazole-4'-                                                             sulphonic acid (4)                                                         79 N-ethyl-N-benzyl-                                                                             "   "      "          "                                       aniline-3'-                                                                   sulphonic acid (4)                                                         80   "             "   "      C.sub.2 H.sub.5                                                                          "                                    81 2-amino-8-hydroxynaphthalene- 6-sulphonic acid (1)                                            "   "                                                                                     ##STR121##                                                                              red                                  82 2-acetoacetylamino-                                                                           H   "      "          yellow                                  naphthalene-5,7-                                                              disulphonic acid (CH.sub.2)                                                83 2-aminonaphthalene-                                                                           H   "      "          orange                                  3,6-disulphonic acid                                                          (1)                                                                        84   "             H   "      C.sub.2 H.sub.5                                                                          "                                    85   "             H   "                                                                                     ##STR122##                                                                              "                                    86 1-hydroxynaphthalene- 3,6,8-trisulphonic acid (2)                                             H   "                                                                                     ##STR123##                                                                              red                                  87   "             H   "      C.sub.2 H.sub.5                                                                          "                                    88 2-hydroxynaphthalene-                                                                         H   "      "          scarlet                                 3,6,8-trisulphonic                                                            acid (1)                                                                   89   "             H   "                                                                                     ##STR124##                                                                              "                                    90   "             H   "                                                                                     ##STR125##                                                                              "                                    91 2-hydroxynaphthalene-                                                                         H   "      CH.sub.3   "                                       3,6,8-trisulphonic                                                            acid (1)                                                                   92 1-hydroxynaphthalene- 3,6,8-trisulphonic acid (2)                                             H   "                                                                                     ##STR126##                                                                              "                                    92a                                                                              1-hydroxynaphthalene- 3,6-disulphonic acid (2)                                                H                                                                                  ##STR127##                                                                           ##STR128##                                                                              "                                    __________________________________________________________________________

example 93

if the tetrazotized 3,8-diaminodibenzofuran is coupled first onto phenoland then onto 2-hydroxynaphthalene-6,8-disulphonic acid under thereaction conditions described under Example 55, after condensing thehydroxyazo dyestuff obtained with p-toluenesulphochloride a dyestuff isobtained with the formula: ##STR129##

This dyestuff dyes natural and synthetic polyamides in pure scarlettones with good fastnesses.

Listed in Table III are the structures of similar dyestuffs which can beproduced following the directions given under Example 93. Theycorrespond to the formula ##STR130##

                                      Table III                                   __________________________________________________________________________        Coupling component                                                                             Radical                                                                             Radical                                            No. R.sub.1      X'  R.sub.2                                                                             R.sub.3    I                                       __________________________________________________________________________     94 2-hydroxynaphthalene- 6,8-disulphonic acid (1)                                             H                                                                                        ##STR131##                                                                              scarlet                                  95   "          H   "     CH.sub.3   "                                        96   "          H                                                                                  ##STR132##                                                                         "          "                                        97   "          H   "     C.sub.2 H.sub.5                                                                          "                                        98   "          H   "                                                                                    ##STR133##                                         99 1-hydroxynaphthalene-                                                                      H   "     "          "                                           3,6-disulphonic acid                                                          (2)                                                                       100   "          H                                                                                  ##STR134##                                                                         "          "                                       101   "          H   "     C.sub.2 H.sub.5                                                                          "                                       102   "          H   "     CH.sub.3   "                                       103 1-hydroxynaphthalene- 3-sulphonic acid (2)                                                 H   "                                                                                    ##STR135##                                                                              "                                       104   "          SO.sub.3 H                                                                        "     "          "                                       105   "          "   "     C.sub.2 H.sub.5                                                                          "                                       106 2-hydroxynaphthalene- 8-sulphonic acid (1)                                                 "   "                                                                                    ##STR136##                                                                              "                                       107   "          "   "     C.sub.2 H.sub.5                                                                          "                                       108 2-hydroxynaphthalene- 8-sulphonic acid (1)                                                 H   "                                                                                    ##STR137##                                                                              "                                       109 1-(4'-sulfophenyl)-                                                                        H   "     "          yellow                                      3-methyl-5-pyrazolone                                                         (4)                                                                       110 1-(2',5'-disulpho)-                                                                        H   "     "          "                                           phenyl-3-methyl-5-                                                            pyrazolone (4)                                                            111   "          H   "     C.sub.2 H.sub.5                                                                          "                                       112   "          H   "     CH.sub.3   "                                       113   "          H                                                                                  ##STR138##                                                                          ##STR139##                                                                              orange                                  114 1-phenyl-3-methyl-5- pyrazolone-3'- sulphonic acid (4)                                     SO.sub.3 H                                                                         ##STR140##                                                                         "          yellow                                  115 1-phenyl-3-methyl-5-                                                                       "   "     "          "                                           aminopyrazole-4'-                                                             sulphonic acid (4)                                                        116 N-ethyl-N-benzyl-                                                                          "   "     "          "                                           aniline-3'-                                                                   sulphonic acid (4)                                                        117   "          "   "     C.sub.2 H.sub.s                                                                          "                                       118 2-amino-8- hydroxynaphthalene- 6-sulphonic acid (1)                                        "   "                                                                                    ##STR141##                                                                              red                                     119 2-acetoacetylamino- naphthalene-5,7- disulphonic acid (CH.sub.                             H)                                                                                 ##STR142##                                                                          ##STR143##                                                                              orange                                  __________________________________________________________________________

EXAMPLE 120

19.8 Parts of 3,8-diaminodibenzofuran are suspended in 150 parts waterand 25 parts hydrochloric acid at 0° - 2°. Then a solution consisting of14 parts sodium nitrate in 60 parts water is dropped into thesuspension, keeping the temperature between 0° and 5°.

After 30 minutes a solution consisting of 13.7 parts para-cresidine, 100parts acetone and 20 parts water is dropped into the tetrazo solution.After 3 hours of stirring at 0° - 5° the pH of the suspension isadjusted to 5 by adding 10 parts sodium acetate. After another hour, asolution consisting of 38.4 parts1-hydroxynaphthalene-3,6,8-trisulphonic acid, 40 parts of a 30% aqueoussodium hydroxide solution and 100 parts water is added to the couplingmixture. The coupling mixture is stirred 4 hours, during which thetemperature may rise to room temperature. The pH of the suspension isadjusted to 7, after which the precipitated product is removed bysuction and washed with an aqueous sodium chloride solution.

Under intensive stirring a neutral solution of the aminodisazo compoundobtained above is allowed to flow into 600 parts water at 0° and admixedwith 18.4 parts of cyanuric chloride which have been suspended in 200parts water and 200 parts ice. The pH of the reaction medium is keptbetween 3 and 4 during this by adding a 15% aqueous sodium carbonatesolution. The condensation product is precipitated with sodium chloride,filtered off and purified with an aqueous sodium chloride solution. Thedyestuff is dried under vacuum at 40° - 50°. In the milled state it is abrown powder, which dissolves in water to a scarlet colour. The dyestuffof the formula: ##STR144## will dye cellulosic fibres to light-, wash-,water- and perspiration-fast shades, and wool, silk and syntheticpolyamide to light-, wash-, water-, perspiration-, mill- anddry-cleaning-fast scarlet tones.

In the Table IV that follows are the structures of further dyestuffswhich can be produced according to the directions under Example 120. Thecorrespond to the formula: ##STR145## in which the symbols R₂₀, R₂₁, X'and R₂₂ represent initial compounds or radicals employed to produce theazo compounds of formula (d) which are given in the appropriate columnsof the table. The colour shade produced on cellulose and polyamide isindicated in a further column I.

                                      Table IV                                    __________________________________________________________________________                                                         Colour                                                                        shade on                 No. R.sub.20        X'    R.sub.21    R.sub.22       polyamide                __________________________________________________________________________                                                         (I)                      121 1-hydroxynaphthalene-3,6- disulphonic acid (2)                                                H                                                                                    ##STR146## 2,4,6-trichloro-1, 3,5-triazine                                                              scarlet                  122    "            H                                                                                    ##STR147##    "            "                       123 2-hydroxynaphthalene-6,8-                                                                     H     "              "            "                           disulphonic acid (1)                                                      124    "            H     "           2,4,5,6-tetra-  "                                                             chloropyrimidine (4)                    125    "            H     "           5-chloro-2,4,6-                                                                               "                                                             trifluoropyrimi-                                                              dine (4)                                126    "            H                                                                                    ##STR148##    "            "                       127    "            H                                                                                    ##STR149## 2,4,6-trichloro- 2,3,5-triazine                                                               ")                      128 2-hydroxynaphthalene-                                                                         H     "              "            "                           3,6,8-trisulphonic acid (1)                                               129 1-phenyl-3-methyl-5-                                                                          H     "              "           goldish-                     pyrazolone-2',5'-                                yellow                       disulphonic acid (4)                                                      130 2-hydroxynaphthalene- 6,8-disulphonic acid (1)                                                H                                                                                    ##STR150##    "           red                      131 2-hydroxynaphthalene- 6,8-disulphonic acid (1)                                                H                                                                                    ##STR151## 2,4,6-trichloro-1,3,5- triazine                                                              goldish- yellow          132 1-hydroxynaphthalene-                                                                         SO.sub.3 H                                                                          "              "           red                          4-sulphonic acid (4)                                                      133 2-hydroxynaphthalene-                                                                         "     "              "            "                           8-sulphonic acid (1)                                                      134    "            H                                                                                    ##STR152##    "            "                       135    "            H                                                                                    ##STR153##    "           red with  bluish                                                              tinge                    136    "            H                                                                                    ##STR154##    "           red                      137 N-ethyl-N-benzylaniline -3'-sulphonic acid (4)                                                H                                                                                    ##STR155## 5-chloro-2,4,6-tri- fluoropyrimidine                                           (4)           purple                   138 2-hydroxynaphthalene-                                                                         H     "              "           red                          6,8-disulphonic acid (1)                                                  139    "            H     "           2,4,6-trichloro-1,3,5-                                                                       red                                                            triazine (2)                            140    "            H     "           2-anilino-4,6- red                                                            dichloro-s-triazine (4)                 141    "            H     "           2-anilino-4,6- red                                                            dichloro-s-triazine-                                                          4'-sulphonic acid                       __________________________________________________________________________                                          (4)                                 

EXAMPLE 142

19.8 Parts of 3,8-diaminodibenzofuran are suspended in 150 parts waterand 25 parts hydrochloric acid at 0° - 2°. Then a solution consisting of14 parts sodium nitrite in 60 parts water is added drop by drop to thesuspension, keeping the temperature between 0° and 5°.

After 30 minutes a solution consisting of 30.4 parts1-hydroxynaphthalene-3,6-disulphonic acid, 8 parts sodium carbonate and200 parts water is added by drops to the tetrazo solution. The couplingmass is stirred 2 hours at 0° - 5°, after which it is poured into avessel containing 13.7 parts p-cresidine, 100 parts acetone, 70 partswater and 25 parts of a 30% aqueous hydrochloric acid solution. Thecoupling mixture is stirred for a further hour, with the pH below 1. Byadding a 25% aqueous sodium acetate solution drop by drop over 3 hours,the pH of the suspension is greatly adjusted to 4.5.

The pH of the suspension is adjusted to 7 with caustic soda solution,after which the precipitated product is removed by suction, washed withan aqueous sodium chloride solution and dried at 100°. The condensationof the aminodisazo compound with cyanuric chloride is effected inanalogous manner to Example 120.

The dyestuff of the formula: ##STR156## will dye cellulosic fibres toshades fast to light, washing, water and perspiration, and wook silk andnylon to scarlet tones which stand up to light, washing, water,perspiration, milling and dry cleaning.

EXAMPLE 143

32 Parts of 3-acetylamino-8-aminodibenzofuran-7-sulphonic acid (obtainedby acetylating 3,8-diaminodibenzofuran-7-sulphonic acid with aceticanhydride in aqueous medium at room temperature) are dissolved in 100parts water and 10 parts 30% aqueous sodium hydroxide solution at roomtemperature. To this solution 3.5 parts sodium nitrate are added,stirring 15 minutes. The solution is then added drop by drop within 30minutes, accompanied by stirring, into 30 parts concentratedhydrochloric acid and 150 parts water at 0° - 5°, continuing to stir theresulting diazo suspension for a further half-hour. A solutionconsisting of 30.4 parts 1-hydroxynaphthalene-3,6-disulphonic acid, 20parts of a 30% aqueous sodium hydroxide solution and 200 parts water isadded dropwise to the diazo suspension. The coupling mass is stirred for2 hours at 0° - 5°. Then the resulting suspension is heated to 90°, andafter adding 50 parts of a 30% aqueous hydrochloric acid it is boiledfor 3 hours at 90°. The precipitated aminoazo product is filtered at 60°and washed with a 10% hydrochloric acid solution, stirred into 200 partswater and dissolved with 20 parts of 30% aqueous sodium hydroxidesolution. To this solution 3 parts sodium nitrate are added, after whichthe nitrite-containing solution is added dropwise to 25 partshydrochloric acid and 150 parts water at 0° - 5°, accompanied bystirring. The resulting diazo suspension is stirred for a furtherhalf-hour.

After this a solution containing 12 parts p-cresidine, 100 parts acetoneand 70 parts water is added to the diazo suspension. By adding a 25%aqueous sodium acetate solution is drops over a period of 3 hours, thepH of the suspension is gradually adjusted to 4.5. The coupling mixtureis stirred 4 hours, during which the temperature may be allowed to riseto room temperature. The pH of the suspension is adjusted to 7, theprecipitated dyestuff is then removed by suction and washed with anaqueous sodium chloride solution. Condensation of the aminodisazodyestuff obtained with cyanuric chloride is effected in analogous mannerto Example 120. The dyestuff is dried under vacuum at 40° - 50°. In themilled state it is a brown powder, which dissolves in water to a scarletcolour. The dyestuff of the formula ##STR157## will dye cellulosicfibres to shades fast to light, washing, water and perspiration andwool, silk and synthetic polyamide to tones which stand up to light,washing, water, perspiration, milling and dry cleaning.

In the Table V that follows, the structures of further dyestuffs aregiven which can be produced according to the directions in Example 143.They correspond to the formula: ##STR158## in which the symbols R₂₃,R₂₄, X' and R₂₅ denote the initial compounds and radicals used in theproduction of the azo compounds of formula (e), which are given in theappropriate columns of the table. The colour shade produced on celluloseand polyamide is indicated in a further column (I).

                                      Table V                                     __________________________________________________________________________    No. R.sub.23        X'    R.sub.24    R.sub.25       I                        __________________________________________________________________________    144 1-hydroxynaphthalene- 3,6-disulphonic acid (2)                                                H                                                                                    ##STR159## 2,4,6-trichloro-1,3,5- triazine                                                              scarlet                  145    "            H                                                                                    ##STR160##    "            "                       146 2-hydroxynaphthalene-                                                                         H     "              "            "                           6,8-disulphonic acid (1)                                                  147    "            H     "           2,4,5,6-tetrachloro-                                                                          "                                                             pyrimidine (4)                          148    "            H     "           5-chloro-2,4,6-tri-                                                                           "                                                             fluoropyrimidine (4)                    149    "            H                                                                                    ##STR161##    "            "                       150    "            H                                                                                    ##STR162## 2,4,6-trichloro-1,3,5- triazine                                                                "                      151 2-hydroxynaphthalene-                                                                         H     "              "            "                           3,6,8-trisulphonic                                                            acid (1)                                                                  152 1-phenyl-3-methyl-                                                                            H     "              "           goldish-                     5-pyrazolone-2',5'-                              yellow                       disulphonic acid (4)                                                      153 2-hydroxynaphthalene- 6,8-disulphonic acid (1)                                                H                                                                                    ##STR163##    "           red                      154    "            H                                                                                    ##STR164##    "            "                       155 1-hydroxynaphthalene- 4-sulphonic acid (2)                                                    SO.sub.3 H                                                                           ##STR165## 2,4,6-trichloro-1,3,5- triazine                                                              red                      156 2-hydroxynaphthalene-                                                                         "     "              "            "                           8-sulphonic acid (1)                                                      157    "            H                                                                                    ##STR166##    "            "                       158    "            H                                                                                    ##STR167##    "           red with bluish                                                               tinge                    159    "            H                                                                                    ##STR168##    "           red                      160 N-ethyl-N- benzylaniline-3'- sulphonic acid (4)                                               H                                                                                    ##STR169## 5-chloro-2,4,6-tri- fluoropyrimidine                                           (4)           purple                   161 2-hydroxynaphthalene-                                                                         H     "              "           red                          6,8-disulphonic                                                               acid (1)                                                                  162    "            H     "           Cyanuric chloride                                                                            red                      163    "            H     "           2-anilino-4,6- red                                                            dichloro-S-                                                                   triazine (4)                            164    "            H     "           2-anilino-4,6- red                                                            dichloro-S-triazine-                                                          4'-sulphonic acid (4)                   164a                                                                              1-hydroxynaphthalene- 3,6-disulphonic acid (2)                                                SO.sub.3 H                                                                           ##STR170## 5-chloro-2,4,6-tri- fluoropyrimidine                                           (4)           red                      164b                                                                              1-phenyl-3,-methyl pyrazolone-5-(2',5'- disulphonic acid                                      H4)                                                                                  ##STR171## 2,4,6-trichloro-1,3, 5-triazine                                                              orange                   __________________________________________________________________________

EXAMPLE 165

75,6 Parts of the dyestuff of Example 100 are dissolved in 1000 partswater at 60° and mixed with 30 parts sodium acetate and 115 parts of amolar copper sulphate solution. Within 3 hours 29 parts of a 40%hydrogen peroxide solution are added drop by drop at a temperature of60° - 65°, maintaining the pH at 5.0 - 5.5 by dropping in a 30% ammoniasolution. The copper complex is precipitated by adding sodium chloride,filtered off and washed with a dilute aqueous sodium chloride solution.The dyestuff of the formula: ##STR172## will dye natural and syntheticpolyamides and celluloses to fast brown tones.

Set out in Table VI are the structures of further dyestuffs which can beproduced according to the directions under Example 165.

    __________________________________________________________________________    Example                                                                              Initial dyestuff                                                       No.    from Example No.                                                                         Complex dyestuff                     I                      __________________________________________________________________________    166    101                                                                                       ##STR173##                          brown                  167    95                                                                                        ##STR174##                          brown                  168    99                                                                                        ##STR175##                          dark brown             169    111                                                                                       ##STR176##                          brown                  170    57                                                                                        ##STR177##                          brown                  171    56                                                                                        ##STR178##                          reddish brown          172    65                                                                                        ##STR179##                          reddish brown          173    74                                                                                        ##STR180##                          reddish                __________________________________________________________________________                                                           brown              

EXAMPLE 174

If in Example 165, p-cresol is used as second coupling component insteadof phenol, the disazo dyestuff can no longer be tosylated. It is howeverpossible to treat the resulting disazo dyestuff under the sameconditions as in Example 165, though with twice the quantity of sodiumacetate, copper sulphate and hydrogen peroxide. The dyestuff obtainedwith the formula: ##STR181## will dye polyamide and cellulose fibers tonavy blue shades.

The following examples can be produced in similar manner to thatdescribed under Example 165.

EXAMPLE 175 ##STR182## EXAMPLE 176 ##STR183## EXAMPLE 177 ##STR184##EXAMPLE 178 ##STR185## EXAMPLE 179 ##STR186## APPLICATION

The compounds of formula I specifically exemplified above may dyevarious substrates using methods conventional in themselves andappropriate to the particular dyestuff and substrate. Thus, for example,dyeing with metal-containing dyestuffs may be carried out in similarways to that described in French Pat. No. 1,570,531, dyeing with anionicdyestuffs in similar ways to that described in Belgian Pat. No. 732,845,dyeing with reactive dyestuffs in similar ways to that described inFrench Pat. No. 1,420,687, and the dyeing of leather in ways similar tothose described in Belgian Pat. No. 745,821.

What is claimed is:
 1. A compound of the formula ##STR187## or a saltthereof, wherein (a) one of R_(2a) and R_(3a) is ##STR188## and theother is ##STR189## b. one of R_(2a) and R_(3a) is ##STR190## c. one ofR_(2a) and R_(3a) is ##STR191## and the other is ##STR192## whereinR_(4a) is hydrogen, hydroxy, sulfo or ##STR193## R_(5a) is hydroxy,carboxy, amino, N-(C₁₋₄ alkyl)amino, N-phenylamino, N,N-di-(C₁₋₄alkyl)amino, N-(C₁₋₄ alkyl) N-(C₁₋₄ alkyl)phenylamino, N-(C₁₋₄alkyl)-N-benzylamino or N-(C₁₋₄ alkyl) N-(C₁₋₄alkyl)phenylsulfamoyl,each R_(6a) is independently amino or hydroxy,each R_(7a) and R_(8a) is independently hydrogen, C₁₋₄ alkyl, halo orsulfo, each R_(9a) is independently hydrogen, C₁₋₄ alkyl, halo or cyano,R_(10a) is hydroxy, amino or acetamido, R_(11a) is hydrogen, carboxy orhydroxy, R_(12a) is hydrogen, sulfo, C₁₋₄ alkyl, C₁₋₄ alkylsulfonyl,C₁₋₄ alkoxy, C₁₋₄ alkylamino, phenylamino, (C₁₋₄ alkoxy)phenylamino ortrimethylphenylamino, each of R_(13a) and R_(14a) is independentlyhydrogen or sulfo, each R_(15a) is independently 2-ethylhexyl, butyl,phenyl, (C₁₋₄ alkyl)phenyl, (C₁₋₄ -alkoxy)phenyl, di-(C₁₋₄ alkoxy)phenylor disulfonaphthyl, R_(16a) is C₁₋₄ alkyl, phenylsulfonyl or (C₁₋₄alkyl)phenylsulfonyl, R_(18a) is hydrogen or C₁₋₄ alkyl, R_(19a) ishydrogen or C₁₋₄ alkyl, R_(20a) is hydrogen, halo, C₁₋₄ alkyl or C₁₋₄alkoxy, R_(21a) is hydrogen or sulfo, and R_(22a) is4,6-dichloro-1,3,5-triazinyl-2,2,6-dichloropyrimidyl-4,2,5,6-trichloropyrimidyl-4,4-chloro-6-(4'-sulfophenylamino)-1,3,5-triazinyl-2,4-chloro-6-(phenylamino)-1,3,5-triazinyl-2or 5-chloro-2,6-difluoropyrimidyl-4, and X is hydrogen or sulfo, withthe provisos that (1) the compound contains 1, 2, 3 or 4 sulfo groups,(2) R_(2a) and R_(3a) are different, and (3) X is hydrogen when R_(3a)is ##STR194##
 2. A compound according to claim 1, or a salt thereof,with the proviso that the compound contains 2, 3 or 4 sulfo groups.
 3. Acompound according to claim 2, or a salt thereof, wherein R_(2a) orR_(3a) is ##STR195##
 4. A compound according to claim 3, or a saltthereof, wherein ##STR196## wherein R_(22a) is4,6-dichloro-1,3,5-triazinyl-2,2,6-dichloropyrimidyl-4,2,5,6-trichloropyrimidyl-4,4-chloro-6-(4'-sulfophenylamino)-1,3,5-triazinyl-2,4-chloro-6-(phenylamino)-1,3,5-triazinyl-2or 5-chloro-2,6-difluoropyrimidyl-4,R_(44a) is hydrogen, methyl, chloroor methoxy, and R_(45a) is hydrogen or methyl.
 5. A compound accordingto claim 3, or a salt thereof, wherein ##STR197## wherein R_(22a) is4,6-dichloro-1,3,5-triazinyl-2,2,6-dichloropyrimidyl-4,2,5,6-trichloropyrimidyl-4,4-chloro-6-(4'-sulfophenylamino)-1,3,5-triazinyl-2,4-chloro-6-(phenylamino)-1,3,5-triazinyl-2or 5-chloro-2,6-difluoropyrimidyl-4, andR_(46a) is hydrogen or sulfo. 6.A compound according to claim 1 having the formula ##STR198## or a saltthereof, wherein one of R_(2a) and R_(3a) is ##STR199## wherein R_(22a)is4,6-dichloro-1,3,5-triazinyl-2,2,6-dichloropyrimidyl-4,2,5,6-trichloropyrimidyl-4,4-chloro-6-(4'-sulfophenylamino)-1,3,5-triazinyl-2,4-chloro-6-(phenylamino)-1,3,5-triazinyl-2or 5-chloro-2,6-difluoropyrimidyl-4,R_(30a) is hydroxy, carboxy, N-C₁₋₄alkylamino, N,N-di-(C₁₋₄ alkyl)amino, N-phenylamino, N-(C₁₋₄alkyl)-N-benzylamino, N-(C₁₋₄ alkyl)-N-(C₁₋₄ alkyl)phenylsulfamoyl or2-hydroxy-5-sulfophenylazo, R_(31a) is hydrogen or hydroxy, with theproviso that R_(31a) is hydroxy when R_(30a) is hydroxy when R_(30a) is2-hydroxy-5-sulfophenylazo, each of R_(33a) and R_(35a) is independentlyhydrogen or chloro, R_(34a) is hydrogen, sulfo or chloro, R_(36a) ishydroxy, amino or acetamido, R_(37a) is hydrogen, hydroxy, carboxy orsulfo, each of R_(38a), R_(39a) and R_(40a) is independently hydrogen orsulfo, with the proviso that at least one and not more than three ofR_(37a), R_(38a), R_(39a) and R_(40a) are sulfo, R_(41a) is pheny,methylphenyl, methoxyphenyl, dimethoxyphenyl, 2-ethylhexyl ordisulfonaphthyl, R_(42a) is methyl, ethyl, phenylsulfonyl orp-methylphenylsulfonyl, R_(43a) is hydrogen or methyl, R_(44a) ishydrogen, methyl, chloro or methoxy, R_(45a) is hydrogen or methyl, andR_(46a) is hydrogen or sulfo.
 7. A compound according to claim 6, or asalt thereof, with the proviso that the compound contains 2, 3 or 4sulfo groups.
 8. a compound according to claim 1, or a salt thereof,wherein at least one of R_(2a) and R_(3a) is ##STR200## with the provisothat R_(2a) and R_(3a) are different.
 9. A compound according to claim8, or a salt thereof, wherein each ##STR201## where each of R_(33a) andR_(35a) is independently hydrogen or chloro, andR_(34a) is hydrogen,sulfo or chloro.
 10. A compound according to claim 8, or a salt thereof,with the proviso that the compound contains 2, 3 or 4 sulfo groups. 11.A compound according to claim 10, or a salt thereof, wherein X ishydrogen.
 12. A compound according to claim 1, or a salt thereof,wherein at least one of R_(2a) and R_(3a) is ##STR202## with the provisothat R_(2a) and R_(3a) are different.
 13. A compound according to claim12, or a salt thereof, wherein each R_(15a) is independently phenyl,methylphenyl, methoxyphenyl, dimethoxyphenyl, 2-ethylhexyl ordisulfonaphthyl.
 14. A compound according to claim 1, or a salt thereof,wherein R_(2a) or R_(3a) is ##STR203##
 15. A compound according to claim1, or a salt thereof, wherein R_(2a) or R_(3a) is ##STR204##
 16. Acompound according to claim 15, or a salt thereof, wherein ##STR205##wherein R_(42a) is methyl, ethyl, phenylsulfonyl orp-methylphenylsulfonyl, andR_(43a) is hydrogen or methyl.
 17. A compoundaccording to claim 15, or a salt thereof, wherein ##STR206## whereinR_(42a) is methyl, ethyl, phenylsulfonyl or p-methylphenylsulfonyl. 18.A compound according to claim 15, or a salt thereof, wherein one ofR_(2a) and R_(3a) is ##STR207## and the other is ##STR208##
 19. Acompound according to claim 18, or a salt thereof, wherein ##STR209##wherein R_(36a) is hydroxy, amino or acetamido,R_(37a) is hydrogen,hydroxy, carboxy or sulfo, and each of R_(38a), R_(39a) and R_(40a) isindependently hydrogen or sulfo, with the proviso that at least one andnot more than three of R_(37a), R_(38a), R_(39a) and R_(40a) are sulfo.20. A compound according to claim 18, or a salt thereof, with theproviso that the compound contains 2, 3 or 4 sulfo groups.
 21. Acompound according to claim 20, or a salt thereof, wherein X ishydrogen.
 22. A compound according to claim 18, or a salt thereof,wherein one ofR_(2a) and R_(3a) is1-hydroxyl-3-sulfonaphthyl-2,1-hydroxy-3,6-disulfonaphthyl-2,1-hydroxy-3,6,8-trisulfonaphthyl-2,2-hydroxy-6-sulfonaphthyl-1,2-hydroxy-8-sulfonaphthyl-1,2-hydroxy-6,8-disulfonaphthyl-1,2-hydroxy-3,6,8-trisulfonaphthyl-1or 2-amino-3,6-disulfonaphthyl-1, the other of R_(2a) and R_(3a) is4-mothoxphenyl, 4-ethoxyphenyl, 4-phenylsulfonyloxyphenyl,4-(4'-methylphenylsulfonyloxy)phenyl, 4-methoxy-2-methylphenyl,4-ethoxy-2-methylphenyl or2-methyl-4-(4'-methylphenylsulfonyloxy)phenyl, and X is hydrogen. 23.The compound according to claim 1 having the formula ##STR210## or asalt thereof.
 24. The compound according to claim 3 having the formula##STR211## or a salt thereof.
 25. The compound according to claim 3having the formula ##STR212## or a salt thereof.
 26. The compoundaccording to claim 3 having the formula ##STR213## or a salt thereof.27. The compound according to claim 8 having the formula ##STR214## or asalt thereof.
 28. The compound according to claim 8 having the formula##STR215## or a salt thereof.
 29. The compound according to claim 18having the formula ##STR216## or a salt thereof.
 30. The compoundaccording to claim 18 having the formula ##STR217## or a salt thereof.31. The compound according to claim 18 having the formula ##STR218## ora salt thereof.
 32. The compound according to claim 18 having theformula ##STR219## or a salt thereof.
 33. The compound according toclaim 18 having the formula ##STR220## or a salt thereof.
 34. Thecompound according to claim 18 having the formula ##STR221## or a saltthereof.
 35. The compound according to claim 18 having the formula##STR222## or a salt thereof.
 36. The compound according to claim 18having the formula ##STR223## or a salt thereof.
 37. The compoundaccording to claim 18 having the formula ##STR224## or a salt thereof.38. The compound according to claim 18 having the formula ##STR225## ora salt thereof.
 39. The compound according to claim 18 having theformula ##STR226## or a salt thereof.
 40. The compound according toclaim 18 having the formula ##STR227## or a salt thereof.
 41. Thecompound according to claim 18 having the formula ##STR228## or a saltthereof.
 42. The compound according to claim 18 having the formula##STR229## or a salt thereof.
 43. The compound according to claim 18having the formula ##STR230## or a salt thereof.
 44. The compoundaccording to claim 18 having the formula ##STR231## or a salt thereof.